Two-component, polyurea compositions are useful in making a wide variety of coatings. These coatings are typically hard, abrasion-, weather- and solvent-resistant. Coating compositions of this type typically include polyisocyanate and isocyanate-reactive compounds, typically primary amines and secondary functional amines such as polyaspartic esters, as coreactants. Polyurea compositions of this type are frequently used in protective coatings for steel and concrete substrates. In an emerging area of technology, high solids coatings are now made using a blend of polyaspartic esters with varying reactivity to obtain compositions that balance application properties against viscosity and cure speed, and yet have very low organic volatile content.